BERKELEY — An attorney for the UC Berkeley student group that invited conservative pundit Ann Coulter to speak on campus April 27 gave the university a 5 p.m. Friday ultimatum to provide the conservative celebrity a forum as originally scheduled, or face possible litigation.

But hours before the deadline, UC Berkeley’s counsel responded that the event sponsors had set the April 27 date without checking with the university and that planning for a Coulter event has been stopped because the sponsors have rejected an alternate date of May 2.

On Wednesday, the university had called off Coulter’s scheduled April 27 appearance because officials said they could not guarantee the safety of her or the people attending. University officials have cited several recent local events that resulted in violence: rallies by both pro- and anti-Donald Trump advocates in downtown Berkeley on March 4 and April 15, and a scheduled appearance by then-Breitbart News editor Milo Yiannopoulos at Cal on Feb. 1 that was cancelled after some masked, black-clad people smashed windows at the student union building and set fires outside.

On Thursday, Chancellor Nicholas Dirks said in a statement that Coulter was invited instead to speak on the afternoon of May 2.

Coulter is the author of “In Trump We Trust” and about a dozen other books.

In a letter to UC Berkeley interim Vice Chancellor for Student Affairs Stephen Sutton, dated Thursday, attorney Harmeet Dhillon characterized the university’s action as a denial of her clients’ First Amendment rights.

Dhillon, of San Francisco-based Dhillon Law Group Inc., represents event sponsor Berkeley College Republicans and event supporter Young America’s Foundation.

“The university’s actions violate fundamental principles of free speech, equal protection and due process guaranteed by the United States Constitution, and will not be tolerated,” Dhillon wrote.

Earlier on Thursday, at a news conference at Haas Pavilion, UC Berkeley spokesman Dan Mogulof said the venue for a May 2 Coulter appearance would be “somewhere on campus property” and that details would be announced once they were worked out with the Coulter organization and the College Republicans.

Dhillon, in her letter, noted that on May 2, students will not be in class and will be studying for finals.

“If UC Berkeley continues to insist on violating the constitutional rights of its students and our clients by marginalizing or banning Ms. Coulter’s speech, we will seek relief in federal court, including claims for injunctive relief and damages,” Dhillon wrote, adding:

“You are on notice of potential imminent litigation.”

The university’s chief campus counsel and associate general counsel, Christopher Patti, responded in a letter to Dhillon on Friday that the Berkeley College Republicans had apparently signed a contract committing to the April 27 Coulter event date without first consulting with the university or getting a security review from its Police Department, and that the campus administration learned of the requested date through newspaper reports.

“The campus continues working on alternatives, however, and determined that a suitable venue could be offered on May 2, while students are still on campus for spring semester,” Patti wrote. “On behalf of (Berkeley College Republicans), you have now rejected the May 2 offer, and so we have discontinued the extensive planning efforts that were underway to hold an event on that date.”

The Berkeley College Republicans did not immediately respond to a request for comment Friday.